Handysnaks, take a look here
post 128 for a copy of the 20 minute circles map posted by Coconutty. A fair bit of the counties you mentioned are covered within those circles. Very difficult to work out numbers unless you plot every town on the map and look up its figures, the big chunks of Wales and North Yorkshire hardly have any population in them.
Love it or hate it, NPAS is here to stay. We just have to live with it. Could be worse, they could have gone for the nine base model or chopped ASU all together.